1. Field of the Invention:
This invention relates to a color video signal processing apparatus in which a composite color television video signal is separated into a luminance signal and a chrominance signal, and the chrominance signal is converted into a line-sequential signal to perform recording or reproducing.
2. Description of the Related Art
In the today's standard color television system, transmission of the color video signal is effected such that two subcarriers of the same frequency (3.58 MHz) but 90.degree. apart in phase are modulated by the respective color difference signals, and then multiplexed on the luminance signal to form a so-called quadrature two-phase-modulated simultaneous signal.
To the recording or reproducing purpose, however, with a view, among others, to allowing the television video signal to be relatively simply handled, a method of transmitting the two color difference signals alternately in each scanning line is adopted. Thus, it is after they have once been converted to a so-called line-sequential signal that the recording or reproduction is carried out.
In this case, the signal processing should include such a step that the original color television video signal is retrieved from the reproduced luminance and line-sequential color difference signals.
For example, the received line-sequential color difference signal is converted to the quadrature two-phase-modulated simultaneous signal in such a way that it is first subjected, without any further treatment, to balanced modulation by the color subcarriers of 90.degree. different phase from each other, and then passed through a comb filter. Such a technique of recovering the simultaneous signal has recently come into use.
However, because the prior art had a mere intention of using the comb filter only for making up the above-described simultaneity, there was a problem in that the effective utilization of the comb filter could not be said to have been completely attained.